Method of purifying oil



`lune 16, 1942. v

- `.L R. MILLER METHOD oF PURIFYING OIL original Filed Jan. 2, 1931 KMA@t if ATTORNEY:

Patented June 16, 1942 l METHOD OF PURIFYING OIL James R. Miller,Pittsburgh, Pa., assignor to Bocjl Corporation, Pittsburgh, Pa., acorporation of Delaware Original application January 2, 1931, Serial No.506,169. Divided and this applicationJanuary 9, 1936, Serial No. 58,343

3 Claims. (Cl. 196-.16),

This invention relates to oil purification and particularly to thepurifying or renovating of crank-case oil of motor vehicles, and thisapplication is a division of my application Serial No. 506,169, filedJanuary 2, 1931, and which has issued as Patent 2,061,666, Nov. 24,1936.

An object of my invention is to provide a method of oil purificationthat is simple and inexpensive, is capable of extended use by owners ofboth relatively small and also large numbers of vehicles, or owners ofgarages, which is capable of practice in simple, relatively inexpensiveand non-bulky apparatus, and which rectifies used lubricating oil byremoving volatile agents contained in or carried by the oil and returnsit to condition for satisfactory re-use.

Heretofore devices for purifying used lubricating oils have been scomplicated and expensive in construction that their field has beenlimited to owners or operators of relatively large fleets of trucks orautomobiles. The initial investment for such devices has been so highthat the savings effected by its use must be relatively large.

The method provided by my invention is of such simplicity that theapparatus needed is simple and the number of parts has been so reduced,compared with prior apparatus, that it may be constructed and operatedat a cost that will render it available to the operator of a relativelysmall number of trucks or automobiles, and the method is suflicientlysimple as to permit it to be operated by relatively unskilled labor.

In the accompanying drawing Fig. 1 is a vertical sectional view of anoil purifier constructed to operate in accordance with my invention; andFig. 2 a similar view of a portion of a modification, v

In accordance with the method provided by this invention usedlubricating oil, such, for example, as that from the crank case of aninternal combustion engine is purified and rendered fit for further useby'heating the oil to a temperature adapted to drive off or cause theliberation of volatile impurities, such as water, fuel, lighthydrocarbons, and the like, and while thus heated agitating it incontact with an impurity-absorbing substance. The volatile impuritiesliberated are withdrawn, thus improving the oil, and the improvement isaided by removal of non-volatile impurities by the absorbing substance.When the treatment has progressed far enough to produce the desiredresult, the oil is treated, as by filtration, to separate the purifiedoil from solid matter.

"- duration of exposure thereto, the original viscosity may be exceeded,although that result will ordinarily not be needed.

In the preferred embodiment of the invention the surface of the oil iscontacted with air,

" whereby better control of final viscosity chara gas-tight cylindricalcasing I5.

acteristics lis attained.

The volatile constituents may be condensed and recovered, and this willbe desirable particularly where large amounts of oil are treated.

The invention may be described further by reference tothe drawing, whichillustrates apparatus for practicing the method. Having reference4thereto, an upright cylindrical metal tank I, which receives the oil tobe treated, is provided with a removable top or cover 2 that is securedthereon by bolts 3. The body of tank I and the cover 2 each have ajacket 4 of asbestos or other suitable heat-insulating material and anouter steel covering 5 for protecting jacket II. Substantially the lowerhalf of tank I is surrounded by an electric heating element 6 that iselectrically insulated from tank I and outer covering 5. The heatingelement 6 is connected to any suitable source of current (not shown). Athermostat I automatically controls the maximum temperature of thecontents of the tank to prevent overheating.

A vertical shaft 8, which extends centrally of tank I, has a loweroutboard bearing 9 and an upper outboard bearing II) which are supportedby a framework I I that is secured to and removable with cover 2. Shaft3 is connected through a universal joint I2 and a short shaft I3 to anelectric motor I4 mounted on the upper end of Shaft I3 extends throughan aperture I6 in cover 2 and a stufng box I'I in the casing I5 and isconnected to the motor shaft by means of a coupling I8. Shaft 8 isprovided at its lower end with an agitating device in the form of apropeller I9 for the purpose of producing a turbulent agitation of theoil and preventingthe deposition of sediment in the bottom of the tank.

Shaft 8 may be provided also with a spiral n 20 which serves to actuatea stream of oil upward around the shaft and fin to be thrown outward atthe end of the spiral iin in the form of spray, as indicated at 2|, tofacilitate the escape of vapors from the oil.

A fan 22 is mounted on shaft I3 within the casing I5 and above apertureI6. Fan 22 draws vapors upwardly through aperture I6 and forces them toow through an outlet pipe 23 into a condenser 2li. Cover 2 is providedwith an inner circular flange 25 for preventing the escape of vaporsbetween cover 2 and the tank.

Cover 2 is provided with an air inlet pipe 2G, and also with an inletfor oil to be treated comprising a funnel 2l and a pipe 28 having avalve 29, The bottom of the tank is provided with an outlet pipe 3Qhaving a valve 3| and that is connected to a gear pump 32 and a filterpress 33.

The apparatus of Fig. 2 differs from that of Fig. l in that cover 2 isprovided with a larger central aperture 35 which is of substantially thesame diameter as that of casing I5. A cylindrical casing 36 is suspendedfrom the cover and is provided with a central opening 3l, through whichextends a shaft 38 that replaces shaft I3 of Fig. l. Fan 22 is mountedon shaft 38 within casing 35. In other respects, the apparatus oi Fig. 2is substantially similar to that of Fig. l.

In the operation of the purifier, oil to be treated is poured in at thetop by means of funnel 21 until the tank is iilled to a desired level,for example as indicated in the drawing. The tank is ordinarily adaptedto receive from iive to ten gallons of oil.

A suitable quantity of clay or fullers earth or other impurity-absorbingmaterial of like nature is added for the purpose of absorbing tarry constituents of the oil and the valve 29 is closed. The clay or fullersearth may, however, be added later, if desired.

The tank is then heated to raise the temperature of the oil to between350 F. and 450 F., depending upon the character of the oil being treatedand the degree to which the lightel` or more volatile constituents areto be removed.A Thermostat 'I may be adjustable or designed for themaximum temperature desired.

Motor IE is in operation during the heating of the oil. Propeller I9actuates oil downwardly against the bottom to prevent the deposition ofsediment and to keep the fullers earth or clay in suspension. Spiral iin23 produces oil spray to increase the surface exposure of the oil andthe liberation of vapors of the volatile elements.

Fan 22 withdraws air and vapors upwardly through aperture I5 into casingI5 and forces them out through pipe 23. Air flows in through the airinlet pipe 26 adjacent the surface of the oil and the circulation of airthus caused by fan 22 assists in the liberation of vapors of gasolineand other volatile ingredients.

Condenser 24, which may be of any suitable or usual type, collects theliquid resulting from the condensable vapors; the condensate flows outthrough a pipe dll. The non-condensable va pors and gases escape througha pipe 4I.

When the oil has been sufciently treated, valve 3I is opened and gearpump 32 is operated to withdraw the oil from the tank I and force itthrough a filter press 33. All sediment and solid material are removedfrom the oil and the latter thus entirely puried and renovated is drawnoff through pipe 42.

The purified oil is now in condition for the same uses for which it wassuitable in its original state. In fact, the treated oil may have aneven higher viscosity than that of the original oil.

The purifier may be reilled after the treated oil is withdrawn and theoperation repeated as often as desired.

The invention thus is simple, easily practiced, requires only simple anduncomplicated apparatus, and efficiently removes undesirable ingredientsof used crank-case oil or oil employed for similar purposes and restoresit to at least its original state of purity and viscosity. The apparatusrequired for practicing the method is extremely simple and may beoperated with entire safety by relatively unskilled labor.

According to the provisions of the patent statutes, I have explained theprinciple and mode of practicing my invention, and have illustrated anddescribed what I now consider to be its best embodiment. However, Idesire to have it understood that, within the scope of the appendedclaims, the invention may be practiced otherwise than as specificallyillustrated and described.

I claim:

1. The method of purifying used lubricating oil, comprising mixing asolid impurity-adsorbing material with said oil, mechanically agitatingthe mixture heated to a temperature to cause volatile impurities to beliberated from the oil, while contacting the surface of the oil bodywith air, withdrawing vapors of volatile impurities from the oil, andtreating the oil to separate solid material therefrom.

2. The method of purifying used lubricating oil, comprising mixing asolid impurity-adsorbing material with said oil, simultaneouslymechanically agitating the mixture and heating it to a temperature atwhich volatile impurities are liberated from the oil, while contactingthe surface of the oil body with air, withdrawing the vapors of volatileimpurities from the oil, separating the solid material from the treatedoil, and recovering oil free from volatile impurities and solid matter.

3. The method of purifying used lubricating oil, comprising mixing asolid impurity-adsorbing or collecting material with said oil,mechanically agitating the mixture and simultaneously heating it at atemperature at which volatile materials are liberated from the oil,while contacting the surface of the oil body with air, withdrawing thevapors of volatile impurities from the oil for condensation ofcondensable constituents, filtering the oil to separate solid mattertherefrom and thereby recovering purified oil free from solid andvolatile impurities.

JAMES R. `MILLER.

